Freight items may be secured in the cargo bay of an aircraft in the longitudinal (x), transverse (y) and height direction (z). For this containers or pallets produced to military standards have engagement recesses in which locking lugs of locking elements can engage. It is important that the locking lugs can be withdrawn from the engagement recesses as easily as possible and without risk of the locking lug seizing, in particular when external forces act on the freight items along a holding direction of the locking lug.
Locking hooks are known which swivel in the x-y plane so that their end locking lugs engage in engagement recesses. On withdrawal of the locking lugs from the engagement recess to release the container, the locking lugs can seize and remain stuck in the engagement recess of the container. When they seize, the locking hooks can no longer be moved completely to the rest position and the containers are not released. This seizing can often only be resolved at great cost and with great force. For example seizing can lead to the freight items having to be moved against the unloading travel direction so that the seizing of the locking lugs can be eliminated.
Some embodiments may have a locking element with a clearly reduced risk that the locking lugs will seize on withdrawal of the lugs from the engagement recesses of the freight items.
In some embodiments the stop surfaces which can be brought into engagement with a stop edge of the engagement recesses of the freight item, separate from opposing stop edges on removal of the locking lugs from the locking recesses. The space required by the locking lugs in the holding direction of the locking lugs is therefore reduced and thus the risk of seizing of the locking lugs in the engagement recesses is clearly reduced in comparison with known locking elements. Also if a force acts on the freight item, the risk of seizing of a pair of locking lugs of a locking element in the present invention is substantially reduced in comparison with previously known locking elements.
In one embodiment the locking lugs of a pair are connected together in opposing directions such that movement of one locking lug carries the other locking lug with it. This ensures that both locking lugs of a pair always move simultaneously. Also the two locking lugs can jointly use many parts of the locking element.
In a further embodiment the locking lugs comprise swivel levers with retaining elements on which the stop surfaces are formed. This type of mounting—in contrast to linear mounting—is very simple.
Preferably the locking lugs can swivel in a vertical plane. As a result the locking lugs can be lowered such that the freight items can pass over them. Also in the cargo bay the locking element can remain attached to the rails which are normally provided at the edges there, even if it is not required, without the locking element hindering the movement and/or securing of the freight item.
The locking element can comprise a fixing device to fix the locking lugs in the locked position and/or rest position. This fixing device prevents unintentional movement of the locking lugs from one position to the other. In one embodiment the fixing device comprises at least one fixing spring element for securing the fixing device in the locked position and/or rest position of the locking lugs. This has amongst others the advantage that the locking lugs can be fixed in the locked position and/or rest position without further action.
The locking element in a further embodiment has at least one movement spring element for movement of the locking lugs from the locked position to the rest position. As a result the locking lugs, if for example not fixed in the working position by the fixing device, are lowered into the rest position which allows the containers to pass over the locks.
In a further embodiment the locking element has at least one starting chamfer in the longitudinal direction of the aircraft (x). The starting chamfers ensure that the freight item does not touch the locking lugs when it is moved below a normal movement plane on the locking element. The starting chamfers convert the horizontal movement of the freight item into a vertical movement and thus raise the freight item if necessary, which prevents damage to the locking element.
The locking lugs can be formed such that parts of a second locking lug can be held in a cavity of a first locking lug such that the stop surfaces are arranged parallel and aligned in the locked position. This not only reduces the space required for the locking lugs in the holding direction, but reduces the common extent of the two locking lugs in each direction.
The cargo bay floor of an aircraft can comprise rails attached to the edges of the cargo bay floor and running in the longitudinal direction of the aircraft (x), and locking elements which are mounted on the rails to secure containers on the cargo bay floor and comprise such elements of the type described here for securing containers to military standards. Also mounted on the cargo bay floor are X/Z locking elements to secure containers to civil standards. As a result containers to military and civil standards can be secured both simultaneously and in successive transport flights.
Locking elements of the type described in the present application for securing containers to military standards in the longitudinal direction of the aircraft (x) at the edges of a cargo bay of an aircraft can be used together with locking elements for securing containers to civil standards on the cargo bay floor. As a result containers to military and civil standards can be used both simultaneously and in successive transport flights.